This list of ancient watermills presents an overview of water-powered grain-mills and industrial mills in the classical antiquity from their Hellenistic beginnings through the Roman imperial period. The watermill is the earliest instance of a machine harnessing natural forces to replace human muscular labour (apart from the sail). As such it holds a special place in the history of technology and also in economic studies where it is associated with growth. The data below spans the period until ca. 500 AD. The vast majority dates to Roman times.